From an isolated research facility at the South Pole to the trading floor of the Tokyo stock exchange, today the world remembered the terrorist attacks that killed not only thousands of Americans, but also hundreds of foreigners.

Nearly 500 foreigners are believed to have died in the attacks. Among them were 67 Britons, two dozen Japanese, 10 Australians. All told, 91 countries lost citizens.

The day began on the other side of the globe from the site of the attacks with a tree-planting ceremony in New Zealand, one of many held on the grounds of those US embassies around the world that remained open despite the threat of a new attack.

In Afghanistan, the country - apart from the United States - most affected by September 11, a small piece of wreckage from the World Trade Centre was buried under the flagpole at the US embassy.

The acting US ambassador, Brad Hanson, announced that September 11 would henceforth be known as Patriot Day and, speaking on behalf of the US president, George Bush, urged Americans to take one moment of silence each year on this date to remember the dead.

However some US embassies in Asia, Africa and the Middle East closed as a result of "credible and specific" threats, and US military bases and embassies in Europe enforced tightened security. Meanwhile in the Malaysian capital of Kuala Lumpur, security was tightened at the Petronas Twin Towers, the world's tallest buildings.

Thousands were evacuated from the nickel-plated towers last year just 12 hours after the attacks in New York because of a bomb hoax.

Cities around the globe paused for moments of silence, while candles were lit and flowers laid outside US embassies from Copenhagen to Moscow to Manila.

In the tiny Newfoundland town of Gander, passengers and air crew who were stranded by the thousands when US airspace was closed following the attacks returned to say thank you.

The Canadian prime minister, Jean Chrétien, and the US ambassador, Paul Cellucci, were among hundreds who gathered at Gander international airport.

Stock markets across Asia opened with brief observances and moments of silence. In Tokyo, screens on the exchange trading floor carried a message of renewed prayer and condolence. European markets followed suit when they opened.

Throughout the day, 180 choirs in 20 time zones began a rolling performance of Mozart's Requiem, starting from the moment when the first hijacked plane flew into the north tower.

US researchers at the South Pole also played the music at their isolated base.

Political leaders - even those who have clashed with the US government over a possible attack on Iraq - expressed their sorrow and solidarity.

"France knows what it owes America," the French president, Jacques Chirac, told a ceremony at the US ambassador's residence in Paris. "The French people stand with all their hearts at the side of the American people."

On the eve of the anniversary, two powerful beams of light were projected into the sky over Paris to honour the memory of victims. The lights are to be projected again tonight.

The Russian president, Vladimir Putin, phoned President George Bush to express his condolences.

"In Russia, they say that time cures, but we cannot forget. We must not forget," Mr Putin said, according to portions of the conversation released on Russian television.

European Union leaders expressed their sorrow at the attacks and said they would stand "side by side" with the US.

"The European Union will not slacken its resolve to contribute to the international community's fight against terrorism," leaders of the 15 EU nations said in a statement.

Pope John Paul II dedicated his weekly general audience at the Vatican to commemorate the attacks. He said that nothing can justify "such an aberration", and urged rich countries to do all they can to put an end to "scandalous" injustices.

"Terrorism is and always will be a show of inhuman ferocity," the Pope told thousands of pilgrims. "It will never be able to solve conflicts among human beings." He repeated the message in several languages.

At Australia's Surfers Paradise, thousands of people led by firefighters and ambulance staff took to the beach to form a human stars and stripes flag.

"It's a sacred time," said Barry Brazel, of the Queensland fire and rescue service, adding that the day holds a special meaning for firefighters of all nationalities.

In Iraq, the state-owned al-Iktisadi newspaper covered its front page with a photograph of a burning World Trade Centre tower and a two-word headline in red: "God's punishment."

"Events like September 11 are sad, but it is an opportunity for the American people to feel what bombing could do to nations," said Ali Ahmed, a 47-year-old who owns a Baghdad stationery shop.

"America has proven it has no respect for nations by wanting to change the government in Iraq. How would an American feel towards somebody who wants to change his government?"